If you’re just looking for a quick calendar date to win a trivia night, here it is: the Siege of Vicksburg ended on July 4, 1863. But history is messy. It isn't just a single day. When people ask when was the Battle of Vicksburg, they’re usually surprised to find out it wasn't a "battle" in the way we think of Gettysburg or Antietam. It was a grueling, miserable, 47-day nightmare that fundamentally broke the Confederacy's back.
It started in May. It ended in July.
In between those months, people were eating rats. That’s not a metaphor.
To understand the timeline, you have to look at the spring of 1863. Ulysses S. Grant, who was honestly a bit of a gambler with his military tactics, had been poking at Vicksburg for months. He tried digging canals. He tried naval bypasses. Nothing worked. Then, in April 1863, he did something incredibly ballsy. He ran his gunboats past the Vicksburg batteries under the cover of night. It was loud, it was fiery, and it was the beginning of the end.
The Campaign vs. The Siege: Getting the Dates Right
Most historians separate the Vicksburg Campaign from the actual siege. The campaign kicked off in earnest on March 29, 1863, when Grant started moving his troops down the west side of the Mississippi River. By the time we get to May, the "battle" starts looking more like a series of violent collisions.
There was the Battle of Port Gibson on May 1st. Then Raymond on the 12th. Jackson fell on the 14th. Then came Champion Hill on May 16th—which many military buffs argue was actually the most decisive fight of the whole ordeal—followed by Big Black River Bridge on the 17th.
By May 19, 1863, Grant had the city surrounded.
He thought he could end it quickly. He ordered a massive assault on May 19th. It failed. He tried again with an even bigger push on May 22, 1863. That one was a bloodbath. Union soldiers were mowed down in front of the Confederate earthworks. Grant realized right then that he couldn't take the city by force without losing his entire army.
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So, he waited.
The formal Siege of Vicksburg lasted from May 22 to July 4, 1863. For forty-seven days, the Union army sat in the dirt and the Confederate army sat in their trenches, and the civilians of Vicksburg literally moved underground.
Life in the Caves
You’ve gotta imagine the heat in Mississippi in June. It’s thick. It’s humid. Now imagine living in a hole in the dirt because Union shells are raining down on your house every few minutes. The residents of Vicksburg dug over 500 caves into the yellow clay hillsides. They called it "Prairie Dog Village."
It wasn't just the soldiers suffering.
By late June, the food was gone. The Confederate troops, led by John C. Pemberton, were down to "pea bread"—a nasty concoction made of ground dried peas and cornmeal that was basically indigestible. Then they started eating the horses. Then the mules. Eventually, there are documented accounts of people eyeing the local stray cats and dogs.
Honestly, the timeline of when was the Battle of Vicksburg is a timeline of starvation. Pemberton received a letter from his own men—signed "Many Soldiers"—basically saying: if you can't feed us, you have to surrender. We can't fight if we can't stand up.
The Surrender That Ruined the Fourth of July
The timing of the surrender is one of those historical coincidences that feels scripted. On July 3, 1863, Pemberton rode out to meet Grant. Ironically, Pemberton was a Northerner (from Pennsylvania) fighting for the South, and Grant was... well, Grant. They sat under a stunted oak tree. Pemberton wanted terms. Grant, true to his nickname "Unconditional Surrender," didn't want to give him much.
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They eventually reached a deal: the Confederate soldiers would be paroled rather than taken as prisoners of war. Grant knew he didn't have the ships to transport 30,000 prisoners North, and he figured these guys were so malnourished and broken they’d just go home and quit fighting anyway.
The official surrender happened on July 4, 1863.
While the North was celebrating Independence Day and the victory at Gettysburg (which happened just a day earlier), the white flag went up over Vicksburg. The Mississippi River was finally, as Abraham Lincoln put it, flowing "unvexed to the sea."
The city of Vicksburg was so salty about the date that they famously didn't celebrate the Fourth of July for another 80 years. It wasn't until World War II that the holiday really made a comeback in the local culture.
Why the Date Matters for Your Visit Today
If you’re planning to visit the Vicksburg National Military Park, the "when" is still relevant. The park is huge. It’s a 16-mile tour road that follows the Union and Confederate lines.
- The USS Cairo: This is a must-see. It’s a literal ironclad gunboat that was sunk in the Yazoo River in December 1862 and raised a century later. It gives you a physical sense of the technology used during that 1863 window.
- The Shirley House: The only surviving wartime structure in the park. It survived the siege while everything around it was leveled.
- The National Cemetery: It holds the remains of 17,000 Union soldiers, the largest number of Civil War interments in the country.
Most people don't realize how much the geography shaped the dates. The city sits on a high bluff. In 1863, the river made a sharp "U" turn right at the city's feet. If you had cannons on those bluffs, you owned the river. Today, the river has actually changed course (the Mississippi is moody like that), and what you see in front of the city is actually the Yazoo Diversion Canal.
Common Misconceptions About the Vicksburg Timeline
A lot of folks get confused and think Vicksburg happened after the war was already winding down. Nope. July 1863 was the absolute tipping point. If Pemberton had held out another month, or if Grant had failed his river crossing in April, the 1864 election might have gone very differently for Lincoln.
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Another weird myth? That the whole thing was just a blockade.
It wasn't. There was constant fighting. Mining was a huge part of the siege. Union troops dug tunnels under the Confederate lines and packed them with 2,200 pounds of gunpowder. On June 25, 1863, they blew it. It created a massive crater. The Union tried to storm through the hole, but the Confederates held them off in some of the most brutal hand-to-hand combat of the war.
Putting It All Together
So, to recap the "when":
The maneuvering started in December 1862.
The real campaign kicked off in March 1863.
The siege itself began on May 22, 1863.
The surrender happened on July 4, 1863.
It’s a long window of time for a single "battle." But that's why Vicksburg is so fascinating. It wasn't a flash of glory; it was a test of will. It was about who could go the longest without food, who could endure the most sun, and who could stay sane while living in a hole in the ground.
When you look at the dates, don't just see numbers on a page. See the heat of a Mississippi June. Hear the constant "whirr" of the Parrot rifles. Feel the desperation of a city that was slowly being choked off from the rest of the world.
Next Steps for Your History Journey
To truly grasp the scale of what happened in 1863, your next step should be looking into the Vicksburg National Military Park's virtual tour or, better yet, mapping out a trip to the site. Seeing the topography of those bluffs in person explains why the siege lasted as long as it did better than any book ever could. You can also research the Official Records of the Union and Confederate Armies online to read the actual telegrams sent between Grant and Washington during those 47 days in the trenches.